1. Technical Field
The present invention relates to a mobile computer system, especially a notebook or a laptop, which is driven alternatively by an external power supply or by battery, comprising a data processing unit and a hard drive to store data. The present invention relates further to a method to operate a mobile computer system, especially a notebook or a laptop, which is driven by an external power supply or by battery and comprising a data processing unit and a hard drive to store data.
2. Description of the Related Art
Mobile computer systems like laptops or notebooks frequently use hard disks to store data. A common problem with mobile equipment as such is the battery lifetime. The hard disk is one of the essential power sinks, as such quite responsible for the overall duration a mobile computer system like a laptop or a notebook can be used.
Several techniques have been successfully employed to optimize the power consumption on laptops. A general idea consists of stopping the hard disk after a specified time from 3 to 60 minutes. This time is typically user selectable because it depends on the user behavior. A large time has to be paid with less usage time, a very short time (e.g. 10 seconds) would have to be paid with low performance as in several programs with hard disk access the hard disk would have to restart (additional power consumption) very often.
As a matter of fact this approach is far from optimum because as a common habit, a user should save his/her work on a document about every 5 minutes—which is quite usual in the professional world. As non-professional users are not familiar with this ‘saving’ attitude, modern programs have invented automatic document backups that perform this ‘save’ task automatically in a specified time frame. This automatism would, however, start the hard disk about every 3-10 minutes depending on the setting.
Summarizing it can be said that the ‘shutdown’ of a hard disk in mobile computers is currently the best state of the art available technology to reduce the power consumption of a hard disk, however it is far from optimal because the shutdown cycle does not cover the demands of applications requirements.